Query Object Considerations

In order to preview a Query Object within the IDE make sure the database connection is set and there's no pending reorganization. Depending on your DBMS you will need to copy certain dependencies to the preview folder, otherwise an error message will be displayed:

The following non-distributable dll was not found: 'IBM.Data.DB2.iSeries.dll'. You need to copy it to '<GX_Installation_Path>\Packages\GXplorer\Preview\bin' in order to preview this query.
The following non-distributable dll was not found: 'libmySQL.dll'. You need to copy it to '<GX_Installation_Path>\Packages\GXplorer\Preview\bin' in order to preview this query.

By default the Query Object supports querying a unique Database referenced by the default Data Stores. If you are using several Data Stores to connect to different database engines, it is not possible to reference attributes from different data stores in a query definition. There's a special case which is supported when several data stores references the same database engine instance.